This invention relates to the activation of silica-titania supported chromium catalysts.
It has long been known to polymerize olefins utilizing a silica supported chromium catalyst. Relatively early in the development of this chromium catalyst technology, it was discovered that the presence of titanium in the support makes it possible to tailor a catalyst to produce a particular type of polymer. Over the years, many techniques have developed directed toward variation in the activation technique in order to produce a catalyst which will impart desired results in the finished polymer. A common factor in most of the techniques relating to chromium olefin polymerization catalysts is that once the catalyst is activated it is given no further treatment but instead is rather carefully protected.